| 摘要 |
A compound of the formula <IMAGE> wherein R1 and R2 are each independently alkyl of 1 to 8 carbon atoms or cycloalkyl of 5 to 6 carbon atoms, R3 is hydrogen, lower alkyl of 1 to 4 carbon atoms or the group -SO2(A2)nR5, R4 and R5 are each independently alkyl of 1 to 18 carbon atoms or cycloalkyl of 5 to 12 carbon atoms, providing that R4 and R5 may each independently be hydrogen when n is 1, A1 and A2 are each independently phenyl, 1-naphthyl, 2-naphthyl, 2-(5,6,7,8-tetrahydro)naphthyl or p-phenylene, and n is 0 or 1 is prepared by reaction of a sulfonyl halide and a 2,6-substituted-4-aminophenol. |
